I'm a Lyman Perma Center collector, so I'll tell you a what I know. These were fine optics for the era they were produced. The Perma Centers were made from 1962-1980 for the 2.5x, 3x, 6x, 8x & 10x & the 4x was made up to 1985. They featured aluminum tubes & constantly centered reticles of #7 crosswire, #5 tapered post & crosswire, #6 tapered post or the optional extra cost Lee Dot. I have owned a 2.5x, 3x, 4x & 6x all in there original boxes with different reticles. As to pricing, I've tracked Ebay & Gunbroker sales over the past few years with prices sold as follows; a 2.5x,$103.50), a 3x,$133.61)in box, a 3x,$112.50), a 4x,$160.25) in box, a 4x,$172.50)in box. Generally, in good condition you'll get over $100.00 & great condition with box $150.00 & up. The higher 8x & 10x magnifications bring even more value. Nick Stroebel's book,'Old Gunsights & Riflescopes', lists the 2.5x at $150.00-$250.00, a little high for todays current market. Ebay watching over time will give you some idea of current values. Hope this helps.